In this paper, aggregation is treated as a logical and/or pseudo-logical operation what is important from many points of view such as adequacy and interpretations.
We study relations on trees defined by first-order constraints over a vocabulary that includes the tree extension relation Ì Ì ¼, holding if and only if every branch of Ì ex...
We develop a calculus for lazy functional programming based on recursion operators associated with data type de nitions. For these operators we derive various algebraic laws that ...